1. Field of the Invention
This invention pertains to methods and apparatus for dissipating fog and more particularly to such methods and apparatus which heat the air thereby evaporating fog.
2. Description of the Related Art
When fog at an airport reduces visibility to the extent that airplanes cannot land and take off, costly delays of freight and passengers occur. It is known that heating fog-laden air increases the capacity of the air for holding water vapor and thus evaporates the fog.
Prior art apparatus for heating the air to evaporate fog and thus increase visibility are known. One such apparatus is disclosed in U.S. Pat. No. 4,125,223 to Carver et al. for an Air Field Space Heater For Fog Dispersal System. The Carver et al. system comprises a space heater which directs streams of hot air across a runway. A similar system to Bertin et al. in U.S. Pat. No. 3,196,822 generates streams of hot air which are directed across the deck of an aircraft carrier.
Other prior art systems utilize heated air which rises by convection. In one such system, a line of small, closely spaced burners are provided to create a row of heat sources.
All of the foregoing suffer from several disadvantages. Primarily, the prior art devices are not able to heat a sufficient volume of air to create adequate visibility for aircraft operations. Secondary problems relate to the length of time necessary to clear fog and the economics of constructing and using such devices. Some of the devices utilize open flames and therefore present safety hazards. In addition, some are not remotely controllable.